Today, corporate and personal information is transmitted from person to person primarily over computer networks. Typically, information in the form of text and graphics is stored within electronic documents, including inter alia Microsoft Word documents, Adobe PDF documents, HTML documents, XML documents, Microsoft Excel spreadsheets, Microsoft PowerPoint presentations and database files. Such documents are generally transmitted as e-mail attachments using a Simple Mail Transport Protocol (SMTP), as File Transfer Protocol (FTP) downloads, as Hyper-Text Transport Protocol (HTTP) downloads, or as Instant Messenger (IM) downloads.
A major security concern is control of access to documents that contain sensitive information. Conventional access control uses passwords to protect document files.
A drawback with prior art access control technology is the lack of ability to trace the distribution route of a document as it travels through computer networks from one or more sources to one or more destinations. Organizations need to track the flow of sensitive documents within the organization, and to track when documents leave the organization and the destinations to which they are sent.